1. Field of the Invention
The present invention concerns a method in order to attach a marker device to an fluoroscopy imaging system (for example an x-ray system) and use it in fluoroscopy imaging. Moreover, the present invention concerns a corresponding marker device, a corresponding fluoroscopy imaging system, and a system that includes both the marker device and the fluoroscopy imaging system.
2. Description of the Prior Art
For the interaction of a fluoroscopy system (for example a C-arm x-ray system) with an optical navigation system, it is necessary (particularly for three-dimensional imaging) for a special marker device or marker geometry (normally a ring-like structure) to be attached to the fluoroscopy system, in particular to the image detector or to the radiation generator of the fluoroscopy system. This marker geometry is formed by multiple active or passive (inactive) markers that are arranged relative to one another in a specifically defined and unique three-dimensional pattern. For example, the active markers can be light-emitting diodes that emit in the infrared spectrum, and the passive markers can be spheres that are reflective in the infrared spectrum.
With the use of this marker geometry, an optical, stereoscopic tracking system or navigation system can unambiguously determine the position in space of the fluoroscopy system (in particular the C-arm) relative to the patient. With the use of previously generated calibration data (with which the weight of the marker device relative to the C-arm is compensated, for example), the unambiguous association of data determined by the fluoroscopy system (for example x-ray data) and navigation data determined by the navigation system is possible with regard to a specific patient. As part of the navigation system, a tracking system usually includes two cameras (or a stereoscopic camera system) and delivers three-dimensional data to the navigation system.
Newer developments in fluoroscopy systems enable marker rings of different manufacturers of navigation systems to be used with the same fluoroscopy system or C-arm. However, an exchange of this marker ring or this marker device involves significant manual effort. Moreover, in addition to the required mechanical reassembly tasks, manual adaptations of the operating software (for example the use of different calibration matrices) of the fluoroscopy system and of the respective navigation system are necessary.
Moreover, fluoroscopy systems are possible that have an integrated marker geometry. If a navigation system of a different manufacturer—and therefore a different marker geometry—is used in such a fluoroscopy system, removal of the integrated marker geometry before use is nearly impossible. This leads to problems in the detection of the marker geometry by the navigation system that is actually used, since henceforth two different marker geometries (the integrated and the newly applied) are located in the field of view of the tracking system (stereoscopic camera), which leads to incorrect detections.